The long term goal of this study is to understand the molecular basis for regulation of the production of toxic oxygen radicals by leukocytes. The investigation will be confined to a biochemical and biophysical analysis of the transient oxidative response of human neutrophils to the chemoattractant N-formyl peptides. Toward this end it will test the hypothesis that the control of the mobility and organization of the plasma membrane protein components (N-formyl peptide receptor, putative regulatory or transducer proteins, and catalytic electron transport proteins) involved in superoxide production plays an essential role in the regulation of this response. Since the cytoskeleton provides major constraints to the mobility and organization of plasma membrane proteins, the investigation will focus on the interaction of this cell structure with the named components of the superoxide generating system. The specific aims include (1) characterization of the receptor-cytoskeletal interaction; (2) investigation of the cytoskeletal interaction of regulatory proteins and catalytic electron transport proteins; (3) analysis of the organization of the plasma membrane with respect to these proteins and the cytoskeleton; (4) demonstration of the functional role of these interactions; and (5) preparation of probes for the future analyses of the mobility and organization of the identified proteins. To achieve these goals cells, plasma membranes, and molecular complexes will be isolated by subcellular fractionation and detergent solubilization. These fractions will be analyzed for content of receptor, cytoskeleton, regulatory and catalytic proteins utilizing photoaffinity labeling and spectroscopic techniques. Specific perturbants of cytoskeletal association and plasma membrane organization will be used to demonstrate the specificity of the cytoskeletal associations and their relevance to the cellular response. An understanding of the role of these mechanisms in regulation of the response may be of significance in determining what interactions between neutrophil surfaces and the tissue environment result in inappropriate activation or lack of termination of the oxidative burst in the inflammed tissue.